Mechanics

CHRYSLER NEW YORKER ENGINE PROBLEM

1990 Chrysler New Yorker • 6 cylinder FWD Automatic • 140,000 miles

I have a 1990 chrysler new yorker with a 3.3 v6 engine. The fuel pump went out so I replaced it and the car ran fine for three weeks then lost power one day on the way home of my 140 mile round trip commute. After letting the car sit for about 15 minutes it started and I drove for 15 miles then it shut down again. After letting it sit again I was able to go about 7 miles. This process continued with each distance decreasing.
I replaced the fuel pump relay and the car ran OK for a few days. Finally I took it to my mechanic who could find no faulty readings but he replaced the crank sensor and reprogramed the computer. The car ran OK again around town (20 mile daily trips) then repeated the same loss of power again. After getting a ride home I returned several hours later and the car started and I was able to drive 10 miles home without trouble.I am at a loss as what to try next. I've considered replacing the fuel pump again (still under warranty fron Auto Zone) but it seems unlikely that is the problem because when the car runs it runs fine. I suspose the fuel pump motor could be getting hot and shutting down but? All vaccum lines are ok. How about the fuel pressure regulator although I replaced it several years ago when I replaced the fuel rail. Replaced fuel filter at same time as fuel pump.
It's like something is heating up and opening a contact which cools down and closes or something similiar with fuel pressure. Would appreciate any ideas you have.
Thanks. Frank Harrison

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Frank harrison
February 24, 2011.




If the Check Engine light has turned on there will be a diagnostic fault code stored in the Engine Computer. That will lead to the circuit with the problem. The crankshaft position sensor is the more common suspect but there is also a camshaft position sensor.

I just solved an identical problem on my '88 Grand Caravan but I'm pretty sure you're going to find a different cause. First of all, unlike GM fuel pumps, Chrysler pumps almost never fail while they are running. The exception would be if the electrical connector wasn't plugged in tightly. I ran into that twice. Usually Chrysler pumps will fail to even start up when you start the engine.

There's actually three different circuits to be familiar with. The fuel pump / fuel supply is one, the ignition coil is another, but most problems occur in the trigger circuit that turns both of them on. The best place to start is by connecting a test light or digital voltmeter to the dark green / orange wire at the coil pack, one of the injectors, or either small terminal on the back of the alternator. Prop the meter or light where you can see it while driving. I put a meter under the right wiper arm, but you could also run a wire inside the car. This setup takes longer but you'll get an indication as soon as the engine dies. The alternative is to jump under the hood after the engine stalls and set the tester up then.

If you'd like to approach it that way let me know and I'll describe what to look for.

Caradiodoc
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Caradiodoc
Feb 24, 2011.
THE CHECK ENGINE LIGHT NEVER CAME ON. After setting for a day it will crank and run fine for several days.

Please describe what to look for in the procedure you talked about and what it would indicate needs replacing?


Tiny
Frank harrison
Feb 25, 2011.
First check for diagnostic fault codes. When the Check Engine light turns on there WILL be at least one code in memory. When the light did not turn on, as in your case, there still COULD be codes. Not all codes result in the light turning on.

Cycle the ignition switch from "off" to "run" three times within five seconds. Shortly after the Check Engine light goes off it will start to flash out two-digit codes. The first one will usually be one flash, a short pause, then two flashes, then a longer pause before the next one starts. Code 12 just means the ignition switch was turned off and can be disregarded. The last one will be code 55 which can also be disregarded. It's the codes in the middle that are important.

To check for spark after the engine stalls, unplug one of the front spark plug wires from the spark plug and hold the brass terminal about 1/4" from a metal part of the engine. Hold it by the rubber part of the wire. Because of the risk of getting jolted, I prefer to poke a screwdriver into the terminal and set it with that 1/4" gap. You should see about two sparks per second while a helper cranks the engine.

If you're alone you can crank the engine from under the hood so you can still see the spark plug wire. I think the '90 models still had metal relays bolted to the left inner fender. If you do, find the one that has a red, brown, black, and one or two yellow wires. That's the starter relay. Unplug it and jumper the red and brown wires in the connector. They will be the two fatter wires. You can use a piece of wire or a stretched out paper clip, but there will be about 20 amps going through it so those could get hot. I use a stretched out cotter pin.

The newer style relays are shown below. If you have that style in the under-hood fuse box, remove the starter relay and connect terminals 30 and 87 in the socket with the cotter pin or paper clip. If you think you might be doing this a lot, a better method is to pop the cover off the relay, reinstall it that way, then just squeeze the contact. It won't hurt to leave the relay cover off for a few weeks. Just put the cover back on the fuse box to keep rain water out while you're driving.

If you find a constant steady stream of sparks yet the engine doesn't run, you have a fuel pump or injector problem. If there is no spark, smell for raw fuel from the tail pipe. If you do smell fuel, you likely have a problem with the ignition coil pack. (The single coil was the cause of the intermittent problem on my 3.0L a few months ago. The symptoms, however, were unusual enough that the coil was ruled out until it finally quit completely).

In the most common scenario you will find no spark and new fuel smell. I always like to double check myself by measuring the voltage on the dark green / orange wire at the coil pack, one of the injectors, or the small terminals on the back of the alternator. A test light works best. You can use a digital voltmeter too but you might miss the first part of the test. If a helper is turning the ignition switch for you, you should see the test light turn on for one second then it will go off. That proves that part of the circuit is working. What's important is it must light up again during engine cranking. If it does not, there is a problem related to the crankshaft position sensor or the camshaft position sensor. Your test light is telling you when the automatic shutdown (ASD) relay is turning on. It turns on for one second after turning on the ignition switch and it turns on again when pulses arrive from those two sensors.

Caradiodoc


Caradiodoc
Feb 25, 2011.
Hi Frank!
Did you ever solve this problem. If so, what was the cause? I have a 1990 Chrysler New Yorker V6 3.3L doing ALL of the same behavior that yours was.


Tiny
Moparfun
Oct 9, 2012.

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